1 /*
2 * Copyright (c) 1998, 2012, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "memory/allocation.inline.hpp"
27 #include "opto/block.hpp"
28 #include "opto/c2compiler.hpp"
29 #include "opto/callnode.hpp"
30 #include "opto/cfgnode.hpp"
31 #include "opto/machnode.hpp"
32 #include "opto/runtime.hpp"
33 #ifdef TARGET_ARCH_MODEL_x86_32
34 # include "adfiles/ad_x86_32.hpp"
35 #endif
36 #ifdef TARGET_ARCH_MODEL_x86_64
37 # include "adfiles/ad_x86_64.hpp"
38 #endif
39 #ifdef TARGET_ARCH_MODEL_sparc
40 # include "adfiles/ad_sparc.hpp"
41 #endif
42 #ifdef TARGET_ARCH_MODEL_zero
43 # include "adfiles/ad_zero.hpp"
44 #endif
45 #ifdef TARGET_ARCH_MODEL_arm
46 # include "adfiles/ad_arm.hpp"
47 #endif
48 #ifdef TARGET_ARCH_MODEL_ppc
49 # include "adfiles/ad_ppc.hpp"
50 #endif
51
52 // Optimization - Graph Style
53
54 //------------------------------implicit_null_check----------------------------
55 // Detect implicit-null-check opportunities. Basically, find NULL checks
56 // with suitable memory ops nearby. Use the memory op to do the NULL check.
57 // I can generate a memory op if there is not one nearby.
58 // The proj is the control projection for the not-null case.
59 // The val is the pointer being checked for nullness or
60 // decodeHeapOop_not_null node if it did not fold into address.
61 void Block::implicit_null_check(PhaseCFG *cfg, Node *proj, Node *val, int allowed_reasons) {
62 // Assume if null check need for 0 offset then always needed
63 // Intel solaris doesn't support any null checks yet and no
64 // mechanism exists (yet) to set the switches at an os_cpu level
65 if( !ImplicitNullChecks || MacroAssembler::needs_explicit_null_check(0)) return;
66
67 // Make sure the ptr-is-null path appears to be uncommon!
68 float f = end()->as_MachIf()->_prob;
69 if( proj->Opcode() == Op_IfTrue ) f = 1.0f - f;
70 if( f > PROB_UNLIKELY_MAG(4) ) return;
71
72 uint bidx = 0; // Capture index of value into memop
73 bool was_store; // Memory op is a store op
74
75 // Get the successor block for if the test ptr is non-null
76 Block* not_null_block; // this one goes with the proj
77 Block* null_block;
78 if (_nodes[_nodes.size()-1] == proj) {
79 null_block = _succs[0];
80 not_null_block = _succs[1];
81 } else {
82 assert(_nodes[_nodes.size()-2] == proj, "proj is one or the other");
83 not_null_block = _succs[0];
84 null_block = _succs[1];
85 }
86 while (null_block->is_Empty() == Block::empty_with_goto) {
87 null_block = null_block->_succs[0];
88 }
89
90 // Search the exception block for an uncommon trap.
91 // (See Parse::do_if and Parse::do_ifnull for the reason
92 // we need an uncommon trap. Briefly, we need a way to
93 // detect failure of this optimization, as in 6366351.)
94 {
95 bool found_trap = false;
96 for (uint i1 = 0; i1 < null_block->_nodes.size(); i1++) {
97 Node* nn = null_block->_nodes[i1];
98 if (nn->is_MachCall() &&
99 nn->as_MachCall()->entry_point() == SharedRuntime::uncommon_trap_blob()->entry_point()) {
100 const Type* trtype = nn->in(TypeFunc::Parms)->bottom_type();
101 if (trtype->isa_int() && trtype->is_int()->is_con()) {
102 jint tr_con = trtype->is_int()->get_con();
103 Deoptimization::DeoptReason reason = Deoptimization::trap_request_reason(tr_con);
104 Deoptimization::DeoptAction action = Deoptimization::trap_request_action(tr_con);
105 assert((int)reason < (int)BitsPerInt, "recode bit map");
106 if (is_set_nth_bit(allowed_reasons, (int) reason)
107 && action != Deoptimization::Action_none) {
108 // This uncommon trap is sure to recompile, eventually.
109 // When that happens, C->too_many_traps will prevent
110 // this transformation from happening again.
111 found_trap = true;
112 }
113 }
114 break;
115 }
116 }
117 if (!found_trap) {
118 // We did not find an uncommon trap.
119 return;
120 }
121 }
122
123 // Check for decodeHeapOop_not_null node which did not fold into address
124 bool is_decoden = ((intptr_t)val) & 1;
125 val = (Node*)(((intptr_t)val) & ~1);
126
127 assert(!is_decoden || (val->in(0) == NULL) && val->is_Mach() &&
128 (val->as_Mach()->ideal_Opcode() == Op_DecodeN), "sanity");
129
130 // Search the successor block for a load or store who's base value is also
131 // the tested value. There may be several.
132 Node_List *out = new Node_List(Thread::current()->resource_area());
133 MachNode *best = NULL; // Best found so far
134 for (DUIterator i = val->outs(); val->has_out(i); i++) {
135 Node *m = val->out(i);
136 if( !m->is_Mach() ) continue;
137 MachNode *mach = m->as_Mach();
138 was_store = false;
139 int iop = mach->ideal_Opcode();
140 switch( iop ) {
141 case Op_LoadB:
142 case Op_LoadUB:
143 case Op_LoadUS:
144 case Op_LoadD:
145 case Op_LoadF:
146 case Op_LoadI:
147 case Op_LoadL:
148 case Op_LoadP:
149 case Op_LoadN:
150 case Op_LoadS:
151 case Op_LoadKlass:
152 case Op_LoadNKlass:
153 case Op_LoadRange:
154 case Op_LoadD_unaligned:
155 case Op_LoadL_unaligned:
156 assert(mach->in(2) == val, "should be address");
157 break;
158 case Op_StoreB:
159 case Op_StoreC:
160 case Op_StoreCM:
161 case Op_StoreD:
162 case Op_StoreF:
163 case Op_StoreI:
164 case Op_StoreL:
165 case Op_StoreP:
166 case Op_StoreN:
167 was_store = true; // Memory op is a store op
168 // Stores will have their address in slot 2 (memory in slot 1).
169 // If the value being nul-checked is in another slot, it means we
170 // are storing the checked value, which does NOT check the value!
171 if( mach->in(2) != val ) continue;
172 break; // Found a memory op?
173 case Op_StrComp:
174 case Op_StrEquals:
175 case Op_StrIndexOf:
176 case Op_AryEq:
177 // Not a legit memory op for implicit null check regardless of
178 // embedded loads
179 continue;
180 default: // Also check for embedded loads
181 if( !mach->needs_anti_dependence_check() )
182 continue; // Not an memory op; skip it
183 if( must_clone[iop] ) {
184 // Do not move nodes which produce flags because
185 // RA will try to clone it to place near branch and
186 // it will cause recompilation, see clone_node().
187 continue;
188 }
189 {
190 // Check that value is used in memory address in
191 // instructions with embedded load (CmpP val1,(val2+off)).
192 Node* base;
193 Node* index;
194 const MachOper* oper = mach->memory_inputs(base, index);
195 if (oper == NULL || oper == (MachOper*)-1) {
196 continue; // Not an memory op; skip it
197 }
198 if (val == base ||
199 val == index && val->bottom_type()->isa_narrowoop()) {
200 break; // Found it
201 } else {
202 continue; // Skip it
203 }
204 }
205 break;
206 }
207 // check if the offset is not too high for implicit exception
208 {
209 intptr_t offset = 0;
210 const TypePtr *adr_type = NULL; // Do not need this return value here
211 const Node* base = mach->get_base_and_disp(offset, adr_type);
212 if (base == NULL || base == NodeSentinel) {
213 // Narrow oop address doesn't have base, only index
214 if( val->bottom_type()->isa_narrowoop() &&
215 MacroAssembler::needs_explicit_null_check(offset) )
216 continue; // Give up if offset is beyond page size
217 // cannot reason about it; is probably not implicit null exception
218 } else {
219 const TypePtr* tptr;
220 if (UseCompressedOops && (Universe::narrow_oop_shift() == 0)) {
221 // 32-bits narrow oop can be the base of address expressions
222 tptr = base->get_ptr_type();
223 } else {
224 // only regular oops are expected here
225 tptr = base->bottom_type()->is_ptr();
226 }
227 // Give up if offset is not a compile-time constant
228 if( offset == Type::OffsetBot || tptr->_offset == Type::OffsetBot )
229 continue;
230 offset += tptr->_offset; // correct if base is offseted
231 if( MacroAssembler::needs_explicit_null_check(offset) )
232 continue; // Give up is reference is beyond 4K page size
233 }
234 }
235
236 // Check ctrl input to see if the null-check dominates the memory op
237 Block *cb = cfg->_bbs[mach->_idx];
238 cb = cb->_idom; // Always hoist at least 1 block
239 if( !was_store ) { // Stores can be hoisted only one block
240 while( cb->_dom_depth > (_dom_depth + 1))
241 cb = cb->_idom; // Hoist loads as far as we want
242 // The non-null-block should dominate the memory op, too. Live
243 // range spilling will insert a spill in the non-null-block if it is
244 // needs to spill the memory op for an implicit null check.
245 if (cb->_dom_depth == (_dom_depth + 1)) {
246 if (cb != not_null_block) continue;
247 cb = cb->_idom;
248 }
249 }
250 if( cb != this ) continue;
251
252 // Found a memory user; see if it can be hoisted to check-block
253 uint vidx = 0; // Capture index of value into memop
254 uint j;
255 for( j = mach->req()-1; j > 0; j-- ) {
256 if( mach->in(j) == val ) {
257 vidx = j;
258 // Ignore DecodeN val which could be hoisted to where needed.
259 if( is_decoden ) continue;
260 }
261 // Block of memory-op input
262 Block *inb = cfg->_bbs[mach->in(j)->_idx];
263 Block *b = this; // Start from nul check
264 while( b != inb && b->_dom_depth > inb->_dom_depth )
265 b = b->_idom; // search upwards for input
266 // See if input dominates null check
267 if( b != inb )
268 break;
269 }
270 if( j > 0 )
271 continue;
272 Block *mb = cfg->_bbs[mach->_idx];
273 // Hoisting stores requires more checks for the anti-dependence case.
274 // Give up hoisting if we have to move the store past any load.
275 if( was_store ) {
276 Block *b = mb; // Start searching here for a local load
277 // mach use (faulting) trying to hoist
278 // n might be blocker to hoisting
279 while( b != this ) {
280 uint k;
281 for( k = 1; k < b->_nodes.size(); k++ ) {
282 Node *n = b->_nodes[k];
283 if( n->needs_anti_dependence_check() &&
284 n->in(LoadNode::Memory) == mach->in(StoreNode::Memory) )
285 break; // Found anti-dependent load
286 }
287 if( k < b->_nodes.size() )
288 break; // Found anti-dependent load
289 // Make sure control does not do a merge (would have to check allpaths)
290 if( b->num_preds() != 2 ) break;
291 b = cfg->_bbs[b->pred(1)->_idx]; // Move up to predecessor block
292 }
293 if( b != this ) continue;
294 }
295
296 // Make sure this memory op is not already being used for a NullCheck
297 Node *e = mb->end();
298 if( e->is_MachNullCheck() && e->in(1) == mach )
299 continue; // Already being used as a NULL check
300
301 // Found a candidate! Pick one with least dom depth - the highest
302 // in the dom tree should be closest to the null check.
303 if( !best ||
304 cfg->_bbs[mach->_idx]->_dom_depth < cfg->_bbs[best->_idx]->_dom_depth ) {
305 best = mach;
306 bidx = vidx;
307
308 }
309 }
310 // No candidate!
311 if( !best ) return;
312
313 // ---- Found an implicit null check
314 extern int implicit_null_checks;
315 implicit_null_checks++;
316
317 if( is_decoden ) {
318 // Check if we need to hoist decodeHeapOop_not_null first.
319 Block *valb = cfg->_bbs[val->_idx];
320 if( this != valb && this->_dom_depth < valb->_dom_depth ) {
321 // Hoist it up to the end of the test block.
322 valb->find_remove(val);
323 this->add_inst(val);
324 cfg->_bbs.map(val->_idx,this);
325 // DecodeN on x86 may kill flags. Check for flag-killing projections
326 // that also need to be hoisted.
327 for (DUIterator_Fast jmax, j = val->fast_outs(jmax); j < jmax; j++) {
328 Node* n = val->fast_out(j);
329 if( n->is_MachProj() ) {
330 cfg->_bbs[n->_idx]->find_remove(n);
331 this->add_inst(n);
332 cfg->_bbs.map(n->_idx,this);
333 }
334 }
335 }
336 }
337 // Hoist the memory candidate up to the end of the test block.
338 Block *old_block = cfg->_bbs[best->_idx];
339 old_block->find_remove(best);
340 add_inst(best);
341 cfg->_bbs.map(best->_idx,this);
342
343 // Move the control dependence
344 if (best->in(0) && best->in(0) == old_block->_nodes[0])
345 best->set_req(0, _nodes[0]);
346
347 // Check for flag-killing projections that also need to be hoisted
348 // Should be DU safe because no edge updates.
349 for (DUIterator_Fast jmax, j = best->fast_outs(jmax); j < jmax; j++) {
350 Node* n = best->fast_out(j);
351 if( n->is_MachProj() ) {
352 cfg->_bbs[n->_idx]->find_remove(n);
353 add_inst(n);
354 cfg->_bbs.map(n->_idx,this);
355 }
356 }
357
358 Compile *C = cfg->C;
359 // proj==Op_True --> ne test; proj==Op_False --> eq test.
360 // One of two graph shapes got matched:
361 // (IfTrue (If (Bool NE (CmpP ptr NULL))))
362 // (IfFalse (If (Bool EQ (CmpP ptr NULL))))
363 // NULL checks are always branch-if-eq. If we see a IfTrue projection
364 // then we are replacing a 'ne' test with a 'eq' NULL check test.
365 // We need to flip the projections to keep the same semantics.
366 if( proj->Opcode() == Op_IfTrue ) {
367 // Swap order of projections in basic block to swap branch targets
368 Node *tmp1 = _nodes[end_idx()+1];
369 Node *tmp2 = _nodes[end_idx()+2];
370 _nodes.map(end_idx()+1, tmp2);
371 _nodes.map(end_idx()+2, tmp1);
372 Node *tmp = new (C) Node(C->top()); // Use not NULL input
373 tmp1->replace_by(tmp);
374 tmp2->replace_by(tmp1);
375 tmp->replace_by(tmp2);
376 tmp->destruct();
377 }
378
379 // Remove the existing null check; use a new implicit null check instead.
380 // Since schedule-local needs precise def-use info, we need to correct
381 // it as well.
382 Node *old_tst = proj->in(0);
383 MachNode *nul_chk = new (C) MachNullCheckNode(old_tst->in(0),best,bidx);
384 _nodes.map(end_idx(),nul_chk);
385 cfg->_bbs.map(nul_chk->_idx,this);
386 // Redirect users of old_test to nul_chk
387 for (DUIterator_Last i2min, i2 = old_tst->last_outs(i2min); i2 >= i2min; --i2)
388 old_tst->last_out(i2)->set_req(0, nul_chk);
389 // Clean-up any dead code
390 for (uint i3 = 0; i3 < old_tst->req(); i3++)
391 old_tst->set_req(i3, NULL);
392
393 cfg->latency_from_uses(nul_chk);
394 cfg->latency_from_uses(best);
395 }
396
397
398 //------------------------------select-----------------------------------------
399 // Select a nice fellow from the worklist to schedule next. If there is only
400 // one choice, then use it. Projections take top priority for correctness
401 // reasons - if I see a projection, then it is next. There are a number of
402 // other special cases, for instructions that consume condition codes, et al.
403 // These are chosen immediately. Some instructions are required to immediately
404 // precede the last instruction in the block, and these are taken last. Of the
405 // remaining cases (most), choose the instruction with the greatest latency
406 // (that is, the most number of pseudo-cycles required to the end of the
407 // routine). If there is a tie, choose the instruction with the most inputs.
408 Node *Block::select(PhaseCFG *cfg, Node_List &worklist, GrowableArray<int> &ready_cnt, VectorSet &next_call, uint sched_slot) {
409
410 // If only a single entry on the stack, use it
411 uint cnt = worklist.size();
412 if (cnt == 1) {
413 Node *n = worklist[0];
414 worklist.map(0,worklist.pop());
415 return n;
416 }
417
418 uint choice = 0; // Bigger is most important
419 uint latency = 0; // Bigger is scheduled first
420 uint score = 0; // Bigger is better
421 int idx = -1; // Index in worklist
422
423 for( uint i=0; i<cnt; i++ ) { // Inspect entire worklist
424 // Order in worklist is used to break ties.
425 // See caller for how this is used to delay scheduling
426 // of induction variable increments to after the other
427 // uses of the phi are scheduled.
428 Node *n = worklist[i]; // Get Node on worklist
429
430 int iop = n->is_Mach() ? n->as_Mach()->ideal_Opcode() : 0;
431 if( n->is_Proj() || // Projections always win
432 n->Opcode()== Op_Con || // So does constant 'Top'
433 iop == Op_CreateEx || // Create-exception must start block
434 iop == Op_CheckCastPP
435 ) {
436 worklist.map(i,worklist.pop());
437 return n;
438 }
439
440 // Final call in a block must be adjacent to 'catch'
441 Node *e = end();
442 if( e->is_Catch() && e->in(0)->in(0) == n )
443 continue;
444
445 // Memory op for an implicit null check has to be at the end of the block
446 if( e->is_MachNullCheck() && e->in(1) == n )
447 continue;
448
449 // Schedule IV increment last.
450 if (e->is_Mach() && e->as_Mach()->ideal_Opcode() == Op_CountedLoopEnd &&
451 e->in(1)->in(1) == n && n->is_iteratively_computed())
452 continue;
453
454 uint n_choice = 2;
455
456 // See if this instruction is consumed by a branch. If so, then (as the
457 // branch is the last instruction in the basic block) force it to the
458 // end of the basic block
459 if ( must_clone[iop] ) {
460 // See if any use is a branch
461 bool found_machif = false;
462
463 for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++) {
464 Node* use = n->fast_out(j);
465
466 // The use is a conditional branch, make them adjacent
467 if (use->is_MachIf() && cfg->_bbs[use->_idx]==this ) {
468 found_machif = true;
469 break;
470 }
471
472 // More than this instruction pending for successor to be ready,
473 // don't choose this if other opportunities are ready
474 if (ready_cnt.at(use->_idx) > 1)
475 n_choice = 1;
476 }
477
478 // loop terminated, prefer not to use this instruction
479 if (found_machif)
480 continue;
481 }
482
483 // See if this has a predecessor that is "must_clone", i.e. sets the
484 // condition code. If so, choose this first
485 for (uint j = 0; j < n->req() ; j++) {
486 Node *inn = n->in(j);
487 if (inn) {
488 if (inn->is_Mach() && must_clone[inn->as_Mach()->ideal_Opcode()] ) {
489 n_choice = 3;
490 break;
491 }
492 }
493 }
494
495 // MachTemps should be scheduled last so they are near their uses
496 if (n->is_MachTemp()) {
497 n_choice = 1;
498 }
499
500 uint n_latency = cfg->_node_latency->at_grow(n->_idx);
501 uint n_score = n->req(); // Many inputs get high score to break ties
502
503 // Keep best latency found
504 if( choice < n_choice ||
505 ( choice == n_choice &&
506 ( latency < n_latency ||
507 ( latency == n_latency &&
508 ( score < n_score ))))) {
509 choice = n_choice;
510 latency = n_latency;
511 score = n_score;
512 idx = i; // Also keep index in worklist
513 }
514 } // End of for all ready nodes in worklist
515
516 assert(idx >= 0, "index should be set");
517 Node *n = worklist[(uint)idx]; // Get the winner
518
519 worklist.map((uint)idx, worklist.pop()); // Compress worklist
520 return n;
521 }
522
523
524 //------------------------------set_next_call----------------------------------
525 void Block::set_next_call( Node *n, VectorSet &next_call, Block_Array &bbs ) {
526 if( next_call.test_set(n->_idx) ) return;
527 for( uint i=0; i<n->len(); i++ ) {
528 Node *m = n->in(i);
529 if( !m ) continue; // must see all nodes in block that precede call
530 if( bbs[m->_idx] == this )
531 set_next_call( m, next_call, bbs );
532 }
533 }
534
535 //------------------------------needed_for_next_call---------------------------
536 // Set the flag 'next_call' for each Node that is needed for the next call to
537 // be scheduled. This flag lets me bias scheduling so Nodes needed for the
538 // next subroutine call get priority - basically it moves things NOT needed
539 // for the next call till after the call. This prevents me from trying to
540 // carry lots of stuff live across a call.
541 void Block::needed_for_next_call(Node *this_call, VectorSet &next_call, Block_Array &bbs) {
542 // Find the next control-defining Node in this block
543 Node* call = NULL;
544 for (DUIterator_Fast imax, i = this_call->fast_outs(imax); i < imax; i++) {
545 Node* m = this_call->fast_out(i);
546 if( bbs[m->_idx] == this && // Local-block user
547 m != this_call && // Not self-start node
548 m->is_MachCall() )
549 call = m;
550 break;
551 }
552 if (call == NULL) return; // No next call (e.g., block end is near)
553 // Set next-call for all inputs to this call
554 set_next_call(call, next_call, bbs);
555 }
556
557 //------------------------------add_call_kills-------------------------------------
558 void Block::add_call_kills(MachProjNode *proj, RegMask& regs, const char* save_policy, bool exclude_soe) {
559 // Fill in the kill mask for the call
560 for( OptoReg::Name r = OptoReg::Name(0); r < _last_Mach_Reg; r=OptoReg::add(r,1) ) {
561 if( !regs.Member(r) ) { // Not already defined by the call
562 // Save-on-call register?
563 if ((save_policy[r] == 'C') ||
564 (save_policy[r] == 'A') ||
565 ((save_policy[r] == 'E') && exclude_soe)) {
566 proj->_rout.Insert(r);
567 }
568 }
569 }
570 }
571
572
573 //------------------------------sched_call-------------------------------------
574 uint Block::sched_call( Matcher &matcher, Block_Array &bbs, uint node_cnt, Node_List &worklist, GrowableArray<int> &ready_cnt, MachCallNode *mcall, VectorSet &next_call ) {
575 RegMask regs;
576
577 // Schedule all the users of the call right now. All the users are
578 // projection Nodes, so they must be scheduled next to the call.
579 // Collect all the defined registers.
580 for (DUIterator_Fast imax, i = mcall->fast_outs(imax); i < imax; i++) {
581 Node* n = mcall->fast_out(i);
582 assert( n->is_MachProj(), "" );
583 int n_cnt = ready_cnt.at(n->_idx)-1;
584 ready_cnt.at_put(n->_idx, n_cnt);
585 assert( n_cnt == 0, "" );
586 // Schedule next to call
587 _nodes.map(node_cnt++, n);
588 // Collect defined registers
589 regs.OR(n->out_RegMask());
590 // Check for scheduling the next control-definer
591 if( n->bottom_type() == Type::CONTROL )
592 // Warm up next pile of heuristic bits
593 needed_for_next_call(n, next_call, bbs);
594
595 // Children of projections are now all ready
596 for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++) {
597 Node* m = n->fast_out(j); // Get user
598 if( bbs[m->_idx] != this ) continue;
599 if( m->is_Phi() ) continue;
600 int m_cnt = ready_cnt.at(m->_idx)-1;
601 ready_cnt.at_put(m->_idx, m_cnt);
602 if( m_cnt == 0 )
603 worklist.push(m);
604 }
605
606 }
607
608 // Act as if the call defines the Frame Pointer.
609 // Certainly the FP is alive and well after the call.
610 regs.Insert(matcher.c_frame_pointer());
611
612 // Set all registers killed and not already defined by the call.
613 uint r_cnt = mcall->tf()->range()->cnt();
614 int op = mcall->ideal_Opcode();
615 MachProjNode *proj = new (matcher.C) MachProjNode( mcall, r_cnt+1, RegMask::Empty, MachProjNode::fat_proj );
616 bbs.map(proj->_idx,this);
617 _nodes.insert(node_cnt++, proj);
618
619 // Select the right register save policy.
620 const char * save_policy;
621 switch (op) {
622 case Op_CallRuntime:
623 case Op_CallLeaf:
624 case Op_CallLeafNoFP:
625 // Calling C code so use C calling convention
626 save_policy = matcher._c_reg_save_policy;
627 break;
628
629 case Op_CallStaticJava:
630 case Op_CallDynamicJava:
631 // Calling Java code so use Java calling convention
632 save_policy = matcher._register_save_policy;
633 break;
634
635 default:
636 ShouldNotReachHere();
637 }
638
639 // When using CallRuntime mark SOE registers as killed by the call
640 // so values that could show up in the RegisterMap aren't live in a
641 // callee saved register since the register wouldn't know where to
642 // find them. CallLeaf and CallLeafNoFP are ok because they can't
643 // have debug info on them. Strictly speaking this only needs to be
644 // done for oops since idealreg2debugmask takes care of debug info
645 // references but there no way to handle oops differently than other
646 // pointers as far as the kill mask goes.
647 bool exclude_soe = op == Op_CallRuntime;
648
649 // If the call is a MethodHandle invoke, we need to exclude the
650 // register which is used to save the SP value over MH invokes from
651 // the mask. Otherwise this register could be used for
652 // deoptimization information.
653 if (op == Op_CallStaticJava) {
654 MachCallStaticJavaNode* mcallstaticjava = (MachCallStaticJavaNode*) mcall;
655 if (mcallstaticjava->_method_handle_invoke)
656 proj->_rout.OR(Matcher::method_handle_invoke_SP_save_mask());
657 }
658
659 add_call_kills(proj, regs, save_policy, exclude_soe);
660
661 return node_cnt;
662 }
663
664
665 //------------------------------schedule_local---------------------------------
666 // Topological sort within a block. Someday become a real scheduler.
667 bool Block::schedule_local(PhaseCFG *cfg, Matcher &matcher, GrowableArray<int> &ready_cnt, VectorSet &next_call) {
668 // Already "sorted" are the block start Node (as the first entry), and
669 // the block-ending Node and any trailing control projections. We leave
670 // these alone. PhiNodes and ParmNodes are made to follow the block start
671 // Node. Everything else gets topo-sorted.
672
673 #ifndef PRODUCT
674 if (cfg->trace_opto_pipelining()) {
675 tty->print_cr("# --- schedule_local B%d, before: ---", _pre_order);
676 for (uint i = 0;i < _nodes.size();i++) {
677 tty->print("# ");
678 _nodes[i]->fast_dump();
679 }
680 tty->print_cr("#");
681 }
682 #endif
683
684 // RootNode is already sorted
685 if( _nodes.size() == 1 ) return true;
686
687 // Move PhiNodes and ParmNodes from 1 to cnt up to the start
688 uint node_cnt = end_idx();
689 uint phi_cnt = 1;
690 uint i;
691 for( i = 1; i<node_cnt; i++ ) { // Scan for Phi
692 Node *n = _nodes[i];
693 if( n->is_Phi() || // Found a PhiNode or ParmNode
694 (n->is_Proj() && n->in(0) == head()) ) {
695 // Move guy at 'phi_cnt' to the end; makes a hole at phi_cnt
696 _nodes.map(i,_nodes[phi_cnt]);
697 _nodes.map(phi_cnt++,n); // swap Phi/Parm up front
698 } else { // All others
699 // Count block-local inputs to 'n'
700 uint cnt = n->len(); // Input count
701 uint local = 0;
702 for( uint j=0; j<cnt; j++ ) {
703 Node *m = n->in(j);
704 if( m && cfg->_bbs[m->_idx] == this && !m->is_top() )
705 local++; // One more block-local input
706 }
707 ready_cnt.at_put(n->_idx, local); // Count em up
708
709 #ifdef ASSERT
710 if( UseConcMarkSweepGC || UseG1GC ) {
711 if( n->is_Mach() && n->as_Mach()->ideal_Opcode() == Op_StoreCM ) {
712 // Check the precedence edges
713 for (uint prec = n->req(); prec < n->len(); prec++) {
714 Node* oop_store = n->in(prec);
715 if (oop_store != NULL) {
716 assert(cfg->_bbs[oop_store->_idx]->_dom_depth <= this->_dom_depth, "oop_store must dominate card-mark");
717 }
718 }
719 }
720 }
721 #endif
722
723 // A few node types require changing a required edge to a precedence edge
724 // before allocation.
725 if( n->is_Mach() && n->req() > TypeFunc::Parms &&
726 (n->as_Mach()->ideal_Opcode() == Op_MemBarAcquire ||
727 n->as_Mach()->ideal_Opcode() == Op_MemBarVolatile) ) {
728 // MemBarAcquire could be created without Precedent edge.
729 // del_req() replaces the specified edge with the last input edge
730 // and then removes the last edge. If the specified edge > number of
731 // edges the last edge will be moved outside of the input edges array
732 // and the edge will be lost. This is why this code should be
733 // executed only when Precedent (== TypeFunc::Parms) edge is present.
734 Node *x = n->in(TypeFunc::Parms);
735 n->del_req(TypeFunc::Parms);
736 n->add_prec(x);
737 }
738 }
739 }
740 for(uint i2=i; i2<_nodes.size(); i2++ ) // Trailing guys get zapped count
741 ready_cnt.at_put(_nodes[i2]->_idx, 0);
742
743 // All the prescheduled guys do not hold back internal nodes
744 uint i3;
745 for(i3 = 0; i3<phi_cnt; i3++ ) { // For all pre-scheduled
746 Node *n = _nodes[i3]; // Get pre-scheduled
747 for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++) {
748 Node* m = n->fast_out(j);
749 if( cfg->_bbs[m->_idx] ==this ) { // Local-block user
750 int m_cnt = ready_cnt.at(m->_idx)-1;
751 ready_cnt.at_put(m->_idx, m_cnt); // Fix ready count
752 }
753 }
754 }
755
756 Node_List delay;
757 // Make a worklist
758 Node_List worklist;
759 for(uint i4=i3; i4<node_cnt; i4++ ) { // Put ready guys on worklist
760 Node *m = _nodes[i4];
761 if( !ready_cnt.at(m->_idx) ) { // Zero ready count?
762 if (m->is_iteratively_computed()) {
763 // Push induction variable increments last to allow other uses
764 // of the phi to be scheduled first. The select() method breaks
765 // ties in scheduling by worklist order.
766 delay.push(m);
767 } else if (m->is_Mach() && m->as_Mach()->ideal_Opcode() == Op_CreateEx) {
768 // Force the CreateEx to the top of the list so it's processed
769 // first and ends up at the start of the block.
770 worklist.insert(0, m);
771 } else {
772 worklist.push(m); // Then on to worklist!
773 }
774 }
775 }
776 while (delay.size()) {
777 Node* d = delay.pop();
778 worklist.push(d);
779 }
780
781 // Warm up the 'next_call' heuristic bits
782 needed_for_next_call(_nodes[0], next_call, cfg->_bbs);
783
784 #ifndef PRODUCT
785 if (cfg->trace_opto_pipelining()) {
786 for (uint j=0; j<_nodes.size(); j++) {
787 Node *n = _nodes[j];
788 int idx = n->_idx;
789 tty->print("# ready cnt:%3d ", ready_cnt.at(idx));
790 tty->print("latency:%3d ", cfg->_node_latency->at_grow(idx));
791 tty->print("%4d: %s\n", idx, n->Name());
792 }
793 }
794 #endif
795
796 uint max_idx = (uint)ready_cnt.length();
797 // Pull from worklist and schedule
798 while( worklist.size() ) { // Worklist is not ready
799
800 #ifndef PRODUCT
801 if (cfg->trace_opto_pipelining()) {
802 tty->print("# ready list:");
803 for( uint i=0; i<worklist.size(); i++ ) { // Inspect entire worklist
804 Node *n = worklist[i]; // Get Node on worklist
805 tty->print(" %d", n->_idx);
806 }
807 tty->cr();
808 }
809 #endif
810
811 // Select and pop a ready guy from worklist
812 Node* n = select(cfg, worklist, ready_cnt, next_call, phi_cnt);
813 _nodes.map(phi_cnt++,n); // Schedule him next
814
815 #ifndef PRODUCT
816 if (cfg->trace_opto_pipelining()) {
817 tty->print("# select %d: %s", n->_idx, n->Name());
818 tty->print(", latency:%d", cfg->_node_latency->at_grow(n->_idx));
819 n->dump();
820 if (Verbose) {
821 tty->print("# ready list:");
822 for( uint i=0; i<worklist.size(); i++ ) { // Inspect entire worklist
823 Node *n = worklist[i]; // Get Node on worklist
824 tty->print(" %d", n->_idx);
825 }
826 tty->cr();
827 }
828 }
829
830 #endif
831 if( n->is_MachCall() ) {
832 MachCallNode *mcall = n->as_MachCall();
833 phi_cnt = sched_call(matcher, cfg->_bbs, phi_cnt, worklist, ready_cnt, mcall, next_call);
834 continue;
835 }
836
837 if (n->is_Mach() && n->as_Mach()->has_call()) {
838 RegMask regs;
839 regs.Insert(matcher.c_frame_pointer());
840 regs.OR(n->out_RegMask());
841
842 MachProjNode *proj = new (matcher.C) MachProjNode( n, 1, RegMask::Empty, MachProjNode::fat_proj );
843 cfg->_bbs.map(proj->_idx,this);
844 _nodes.insert(phi_cnt++, proj);
845
846 add_call_kills(proj, regs, matcher._c_reg_save_policy, false);
847 }
848
849 // Children are now all ready
850 for (DUIterator_Fast i5max, i5 = n->fast_outs(i5max); i5 < i5max; i5++) {
851 Node* m = n->fast_out(i5); // Get user
852 if( cfg->_bbs[m->_idx] != this ) continue;
853 if( m->is_Phi() ) continue;
854 if (m->_idx >= max_idx) { // new node, skip it
855 assert(m->is_MachProj() && n->is_Mach() && n->as_Mach()->has_call(), "unexpected node types");
856 continue;
857 }
858 int m_cnt = ready_cnt.at(m->_idx)-1;
859 ready_cnt.at_put(m->_idx, m_cnt);
860 if( m_cnt == 0 )
861 worklist.push(m);
862 }
863 }
864
865 if( phi_cnt != end_idx() ) {
866 // did not schedule all. Retry, Bailout, or Die
867 Compile* C = matcher.C;
868 if (C->subsume_loads() == true && !C->failing()) {
869 // Retry with subsume_loads == false
870 // If this is the first failure, the sentinel string will "stick"
871 // to the Compile object, and the C2Compiler will see it and retry.
872 C->record_failure(C2Compiler::retry_no_subsuming_loads());
873 }
874 // assert( phi_cnt == end_idx(), "did not schedule all" );
875 return false;
876 }
877
878 #ifndef PRODUCT
879 if (cfg->trace_opto_pipelining()) {
880 tty->print_cr("#");
881 tty->print_cr("# after schedule_local");
882 for (uint i = 0;i < _nodes.size();i++) {
883 tty->print("# ");
884 _nodes[i]->fast_dump();
885 }
886 tty->cr();
887 }
888 #endif
889
890
891 return true;
892 }
893
894 //--------------------------catch_cleanup_fix_all_inputs-----------------------
895 static void catch_cleanup_fix_all_inputs(Node *use, Node *old_def, Node *new_def) {
896 for (uint l = 0; l < use->len(); l++) {
897 if (use->in(l) == old_def) {
898 if (l < use->req()) {
899 use->set_req(l, new_def);
900 } else {
901 use->rm_prec(l);
902 use->add_prec(new_def);
903 l--;
904 }
905 }
906 }
907 }
908
909 //------------------------------catch_cleanup_find_cloned_def------------------
910 static Node *catch_cleanup_find_cloned_def(Block *use_blk, Node *def, Block *def_blk, Block_Array &bbs, int n_clone_idx) {
911 assert( use_blk != def_blk, "Inter-block cleanup only");
912
913 // The use is some block below the Catch. Find and return the clone of the def
914 // that dominates the use. If there is no clone in a dominating block, then
915 // create a phi for the def in a dominating block.
916
917 // Find which successor block dominates this use. The successor
918 // blocks must all be single-entry (from the Catch only; I will have
919 // split blocks to make this so), hence they all dominate.
920 while( use_blk->_dom_depth > def_blk->_dom_depth+1 )
921 use_blk = use_blk->_idom;
922
923 // Find the successor
924 Node *fixup = NULL;
925
926 uint j;
927 for( j = 0; j < def_blk->_num_succs; j++ )
928 if( use_blk == def_blk->_succs[j] )
929 break;
930
931 if( j == def_blk->_num_succs ) {
932 // Block at same level in dom-tree is not a successor. It needs a
933 // PhiNode, the PhiNode uses from the def and IT's uses need fixup.
934 Node_Array inputs = new Node_List(Thread::current()->resource_area());
935 for(uint k = 1; k < use_blk->num_preds(); k++) {
936 inputs.map(k, catch_cleanup_find_cloned_def(bbs[use_blk->pred(k)->_idx], def, def_blk, bbs, n_clone_idx));
937 }
938
939 // Check to see if the use_blk already has an identical phi inserted.
940 // If it exists, it will be at the first position since all uses of a
941 // def are processed together.
942 Node *phi = use_blk->_nodes[1];
943 if( phi->is_Phi() ) {
944 fixup = phi;
945 for (uint k = 1; k < use_blk->num_preds(); k++) {
946 if (phi->in(k) != inputs[k]) {
947 // Not a match
948 fixup = NULL;
949 break;
950 }
951 }
952 }
953
954 // If an existing PhiNode was not found, make a new one.
955 if (fixup == NULL) {
956 Node *new_phi = PhiNode::make(use_blk->head(), def);
957 use_blk->_nodes.insert(1, new_phi);
958 bbs.map(new_phi->_idx, use_blk);
959 for (uint k = 1; k < use_blk->num_preds(); k++) {
960 new_phi->set_req(k, inputs[k]);
961 }
962 fixup = new_phi;
963 }
964
965 } else {
966 // Found the use just below the Catch. Make it use the clone.
967 fixup = use_blk->_nodes[n_clone_idx];
968 }
969
970 return fixup;
971 }
972
973 //--------------------------catch_cleanup_intra_block--------------------------
974 // Fix all input edges in use that reference "def". The use is in the same
975 // block as the def and both have been cloned in each successor block.
976 static void catch_cleanup_intra_block(Node *use, Node *def, Block *blk, int beg, int n_clone_idx) {
977
978 // Both the use and def have been cloned. For each successor block,
979 // get the clone of the use, and make its input the clone of the def
980 // found in that block.
981
982 uint use_idx = blk->find_node(use);
983 uint offset_idx = use_idx - beg;
984 for( uint k = 0; k < blk->_num_succs; k++ ) {
985 // Get clone in each successor block
986 Block *sb = blk->_succs[k];
987 Node *clone = sb->_nodes[offset_idx+1];
988 assert( clone->Opcode() == use->Opcode(), "" );
989
990 // Make use-clone reference the def-clone
991 catch_cleanup_fix_all_inputs(clone, def, sb->_nodes[n_clone_idx]);
992 }
993 }
994
995 //------------------------------catch_cleanup_inter_block---------------------
996 // Fix all input edges in use that reference "def". The use is in a different
997 // block than the def.
998 static void catch_cleanup_inter_block(Node *use, Block *use_blk, Node *def, Block *def_blk, Block_Array &bbs, int n_clone_idx) {
999 if( !use_blk ) return; // Can happen if the use is a precedence edge
1000
1001 Node *new_def = catch_cleanup_find_cloned_def(use_blk, def, def_blk, bbs, n_clone_idx);
1002 catch_cleanup_fix_all_inputs(use, def, new_def);
1003 }
1004
1005 //------------------------------call_catch_cleanup-----------------------------
1006 // If we inserted any instructions between a Call and his CatchNode,
1007 // clone the instructions on all paths below the Catch.
1008 void Block::call_catch_cleanup(Block_Array &bbs, Compile* C) {
1009
1010 // End of region to clone
1011 uint end = end_idx();
1012 if( !_nodes[end]->is_Catch() ) return;
1013 // Start of region to clone
1014 uint beg = end;
1015 while(!_nodes[beg-1]->is_MachProj() ||
1016 !_nodes[beg-1]->in(0)->is_MachCall() ) {
1017 beg--;
1018 assert(beg > 0,"Catch cleanup walking beyond block boundary");
1019 }
1020 // Range of inserted instructions is [beg, end)
1021 if( beg == end ) return;
1022
1023 // Clone along all Catch output paths. Clone area between the 'beg' and
1024 // 'end' indices.
1025 for( uint i = 0; i < _num_succs; i++ ) {
1026 Block *sb = _succs[i];
1027 // Clone the entire area; ignoring the edge fixup for now.
1028 for( uint j = end; j > beg; j-- ) {
1029 // It is safe here to clone a node with anti_dependence
1030 // since clones dominate on each path.
1031 Node *clone = _nodes[j-1]->clone();
1032 sb->_nodes.insert( 1, clone );
1033 bbs.map(clone->_idx,sb);
1034 }
1035 }
1036
1037
1038 // Fixup edges. Check the def-use info per cloned Node
1039 for(uint i2 = beg; i2 < end; i2++ ) {
1040 uint n_clone_idx = i2-beg+1; // Index of clone of n in each successor block
1041 Node *n = _nodes[i2]; // Node that got cloned
1042 // Need DU safe iterator because of edge manipulation in calls.
1043 Unique_Node_List *out = new Unique_Node_List(Thread::current()->resource_area());
1044 for (DUIterator_Fast j1max, j1 = n->fast_outs(j1max); j1 < j1max; j1++) {
1045 out->push(n->fast_out(j1));
1046 }
1047 uint max = out->size();
1048 for (uint j = 0; j < max; j++) {// For all users
1049 Node *use = out->pop();
1050 Block *buse = bbs[use->_idx];
1051 if( use->is_Phi() ) {
1052 for( uint k = 1; k < use->req(); k++ )
1053 if( use->in(k) == n ) {
1054 Node *fixup = catch_cleanup_find_cloned_def(bbs[buse->pred(k)->_idx], n, this, bbs, n_clone_idx);
1055 use->set_req(k, fixup);
1056 }
1057 } else {
1058 if (this == buse) {
1059 catch_cleanup_intra_block(use, n, this, beg, n_clone_idx);
1060 } else {
1061 catch_cleanup_inter_block(use, buse, n, this, bbs, n_clone_idx);
1062 }
1063 }
1064 } // End for all users
1065
1066 } // End of for all Nodes in cloned area
1067
1068 // Remove the now-dead cloned ops
1069 for(uint i3 = beg; i3 < end; i3++ ) {
1070 _nodes[beg]->disconnect_inputs(NULL, C);
1071 _nodes.remove(beg);
1072 }
1073
1074 // If the successor blocks have a CreateEx node, move it back to the top
1075 for(uint i4 = 0; i4 < _num_succs; i4++ ) {
1076 Block *sb = _succs[i4];
1077 uint new_cnt = end - beg;
1078 // Remove any newly created, but dead, nodes.
1079 for( uint j = new_cnt; j > 0; j-- ) {
1080 Node *n = sb->_nodes[j];
1081 if (n->outcnt() == 0 &&
1082 (!n->is_Proj() || n->as_Proj()->in(0)->outcnt() == 1) ){
1083 n->disconnect_inputs(NULL, C);
1084 sb->_nodes.remove(j);
1085 new_cnt--;
1086 }
1087 }
1088 // If any newly created nodes remain, move the CreateEx node to the top
1089 if (new_cnt > 0) {
1090 Node *cex = sb->_nodes[1+new_cnt];
1091 if( cex->is_Mach() && cex->as_Mach()->ideal_Opcode() == Op_CreateEx ) {
1092 sb->_nodes.remove(1+new_cnt);
1093 sb->_nodes.insert(1,cex);
1094 }
1095 }
1096 }
1097 }